Probably composed in the late 14th/early 15th century, Lebhar Breac (as it is commonly known) is a collection of ecclesiatic writings in both Middle Irish and Latin, compiled by the scribe Murchadh Riabhach O'Cuindlis. It has several saints' lives, in particular those of Sts. Patrick, Brigid, and Columba, as well as "The Martyrology of Oengus the Culdee." It also contains numerous homilies, hymns, and ecclesiastical legends, including what some think is the oldest Marian litany. It was held by the MacEgans, a brehon family, at Dun Doighre in Galway--hense one of the book's many titles.

A facimilie was made, called Leabhar Breac, the Speckled Book, otherwise styled Leabhar Mór Dúna Doighre, the Great Book of Dun Doighre. Dublin 1876.